In this Phase II proposal we will perform validation, testing, software development, and technical innovation for a commercially acceptable pediatric activity monitoring instrument. We shall re-validate the designed unit and incorporate improved features, specifically, 2-channel storage of high and low sensitivity. A user-friendly software package will be developed for the set-up of device, data recovery, data presentation, data editing, and statistical analysis, as well as pediatric clinical report, which will be generated from the collected data. A detailed user manual will also be written to include representative examples of tracings for the varied population selected for monitoring along with normative ranges. Human engineering will be evaluated for different ages, size of patients, and location of sensors. Up to 900 sample recordings of 3-to-5 day duration will be collected in a natural environment. The core standard sample will consist of an equal distribution between males and females in each age group (3 months to 10 years), and minorities will be represented. Clinical groups shall include infants with fetal cocaine exposure, infants with colic or excessive crying, infants with primary sleep disorders, children with attention deficit hyperactivity disorder, offspring of depressed and obsessive compulsive disorder, and children with psychiatric diagnoses. Groups will be followed after treatment.